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/*
* Copyright (c) 2016-2022, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <bl1/bl1.h>
#include <common/bl_common.h>
#include <context.h>
#include <lib/xlat_tables/xlat_tables.h>
#include <smccc_helpers.h>
#include <smccc_macros.S>
.globl bl1_aarch32_smc_handler
func bl1_aarch32_smc_handler
/* On SMC entry, `sp` points to `smc_ctx_t`. Save `lr`. */
str lr, [sp, #SMC_CTX_LR_MON]
/* ------------------------------------------------
* SMC in BL1 is handled assuming that the MMU is
* turned off by BL2.
* ------------------------------------------------
*/
/* ----------------------------------------------
* Detect if this is a RUN_IMAGE or other SMC.
* ----------------------------------------------
*/
mov lr, #BL1_SMC_RUN_IMAGE
cmp lr, r0
bne smc_handler
/* ------------------------------------------------
* Make sure only Secure world reaches here.
* ------------------------------------------------
*/
ldcopr r8, SCR
tst r8, #SCR_NS_BIT
blne report_exception
/* ---------------------------------------------------------------------
* Pass control to next secure image.
* Here it expects r1 to contain the address of a entry_point_info_t
* structure describing the BL entrypoint.
* ---------------------------------------------------------------------
*/
mov r8, r1
mov r0, r1
bl bl1_print_next_bl_ep_info
#if SPIN_ON_BL1_EXIT
bl print_debug_loop_message
debug_loop:
b debug_loop
#endif
mov r0, r8
bl bl1_plat_prepare_exit
stcopr r0, TLBIALL
dsb sy
isb
/*
* Extract PC and SPSR based on struct `entry_point_info_t`
* and load it in LR and SPSR registers respectively.
*/
ldr lr, [r8, #ENTRY_POINT_INFO_PC_OFFSET]
ldr r1, [r8, #(ENTRY_POINT_INFO_PC_OFFSET + 4)]
msr spsr_xc, r1
/* Some BL32 stages expect lr_svc to provide the BL33 entry address */
cps #MODE32_svc
ldr lr, [r8, #ENTRY_POINT_INFO_LR_SVC_OFFSET]
cps #MODE32_mon
add r8, r8, #ENTRY_POINT_INFO_ARGS_OFFSET
ldm r8, {r0, r1, r2, r3}
exception_return
endfunc bl1_aarch32_smc_handler
/* -----------------------------------------------------
* Save Secure/Normal world context and jump to
* BL1 SMC handler.
* -----------------------------------------------------
*/
func smc_handler
/* -----------------------------------------------------
* Save the GP registers.
* -----------------------------------------------------
*/
smccc_save_gp_mode_regs
/*
* `sp` still points to `smc_ctx_t`. Save it to a register
* and restore the C runtime stack pointer to `sp`.
*/
mov r6, sp
ldr sp, [r6, #SMC_CTX_SP_MON]
ldr r0, [r6, #SMC_CTX_SCR]
and r7, r0, #SCR_NS_BIT /* flags */
/* Switch to Secure Mode */
bic r0, #SCR_NS_BIT
stcopr r0, SCR
isb
/* If caller is from Secure world then turn on the MMU */
tst r7, #SCR_NS_BIT
bne skip_mmu_on
/* Turn on the MMU */
mov r0, #DISABLE_DCACHE
bl enable_mmu_svc_mon
/*
* Invalidate `smc_ctx_t` in data cache to prevent dirty data being
* used.
*/
mov r0, r6
mov r1, #SMC_CTX_SIZE
bl inv_dcache_range
/* Enable the data cache. */
ldcopr r9, SCTLR
orr r9, r9, #SCTLR_C_BIT
stcopr r9, SCTLR
isb
skip_mmu_on:
/* Prepare arguments for BL1 SMC wrapper. */
ldr r0, [r6, #SMC_CTX_GPREG_R0] /* smc_fid */
mov r1, #0 /* cookie */
mov r2, r6 /* handle */
mov r3, r7 /* flags */
bl bl1_smc_wrapper
/* Get the smc_context for next BL image */
bl smc_get_next_ctx
mov r4, r0
/* Only turn-off MMU if going to secure world */
ldr r5, [r4, #SMC_CTX_SCR]
tst r5, #SCR_NS_BIT
bne skip_mmu_off
/* Disable the MMU */
bl disable_mmu_icache_secure
stcopr r0, TLBIALL
dsb sy
isb
skip_mmu_off:
/* -----------------------------------------------------
* Do the transition to next BL image.
* -----------------------------------------------------
*/
mov r0, r4
monitor_exit
endfunc smc_handler
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